🚀 go-pugleaf

In article <2011@randvax.UUCP> lacasse@blaise.UUCP (Mark LaCasse) writes:
>what I would like and can't find are PROPORTIONAL valves
>of some sort.  Something like a gate value with a stepper
>motor attached...

Good proportional valves are probably much more expensive than simple
on-off valves, since the market is much smaller.  As was suggested a
while ago when this came up, one thing you can do is combine several
on-off valves in parallel, with flow restrictors, to build a hydraulic
digital-to-analog converter; it's not true proportional control but it
might be close enough.
-- 
Mars in 1980s:  USSR, 2 tries, |     Henry Spencer at U of Toronto Zoology
2 failures; USA, 0 tries.      | uunet!attcan!utzoo!henry henry@zoo.toronto.edu